I have a problem to solve this question. I thought I should eliminate the existential first but it seems not work..Not sure how to use the existential condition to prove the later one.
Here's the rule for existential elimination,
1: Ev.p(v) // use E for ∃
2: Av.(p(v) => q) //use A for ∀
EE 1,2: q
And the Fitch system provides new method also, it calls equalization introduction and equalization elimination..But I don't know how to use it..Since the lecture doesn't have any information about that..If someone know, could you tell me??
Thanks for your help!!